1. Field of the Invention
This invention relates to an auto-lock slider for a concealed slide fastener, and more particularly to such an auto-lock slider in which a locking lever with a locking claw and a leaf spring as a resilient member are separate from each other and in which one end of the locking lever and the leaf spring are received in the upper portion of a guide lug of a slider body.
2. Description of the Related Art
In a conventional auto-lock slider for a concealed slide fastener, as shown in FIG. 9 of the accompanying drawings, a slider body 30 has in the upper portion of a guide lug 31 for guiding a locking lever 32, a vertical groove 33 for receiving the locking lever 32, and the guide lug 31 has in its front portion a hole 35 in which a coil spring 34 is received. The coil spring 34 is pressed against a rear end of the locking lever 32. The locking lever 32 is pivotally mounted at its center and has at its front end a locking claw 36 in the base of which a pintle 37 of a pull tab is inserted so that the locking claw 36 of the locking lever 32 can pivotally move vertically.
In another conventional auto-lock slider (Republic of China Patent Publication No. 20633), as shown in FIG. 10, a slider body 41 has in the upper portion of a guide lug 42 a vertical groove 44 for receiving a generally M-shape locking lever 43, and the guide lug 42 has in its center a hole 46 in which a coil spring 45 is received. The coil spring 45 is held in the hole 46 by clinching the upper end of the hole 46 in such a manner that the coil spring 45 is pressed against a central recess of the M shape of the locking lever 43. A pintle 48 of a pull tab is inserted in the base of a locking claw 47 of the locking lever 43 so that the locking claw 47 can pivotally move vertically.
In assembling of the first-named conventional auto-lock slider, firstly the coil spring 34 is received in the hole 35 and then the locking lever 32 is inserted into the vertical groove 33 with the rear end pressed downwardly until a pivot hole 38 of the locking lever 32 is aligned with pivot holes 39 of the guide lug 31, whereupon a hollow pivot 40 is inserted through the pivot holes 38, 39 and is then clinched at opposite ends. Partly since the aligning of the pivot holes and the clinching of the hollow pivot require complex works, and partly since the number of components of the slider is large, an inexpensive slider could not be obtained.
With the second-named conventional auto-lock slider, since the locking lever 43 is held in position simply by pressing its center with the coil spring, the positioning of the locking lever 43 is very unstable. More specifically, since an anchor portion 49 of the locking lever 43 is not held from the upper side with anything, the anchor portion 49 will float upwardly against the resilience of the coil spring 45 about the pivot 48 as a force is exerted on the front end of the locking lever 43, namely, as a force is exerted on the slider in the direction of opening the slide fastener without operating the pull tab, thus disconnecting the locking lever 43 from the guide lug 42 by accident, which would by a cause for failure. Further, this conventional slider is very laborious to assemble.